Conure biting my shirt and neck?

my dusky conure that i have had for a month started biting my neck yesterday and shirt. yesterday i held her for a just a few minutes on my shoulder and she started doing something like biting my shirt, and today she was biting my neck pretty hard and getting mad. the thing is she hasnt done it to anyone else, even thought i hold her the majority of the time, my brother is the owner and he takes her out alone with just him and other times its me my brother and mom, and she sticks with me the whole time until somebody else takes her. shes never been a biter to me, only letting out a little noise if i bug her or puts my finger in her mouth but never bites(unless its my ear). we have 2 sun conures but shes my first female conure so i was wondering if its maybe hormonal?